Work-related asthma--38 states and District of Columbia, 2006-2009

Work-related asthma (WRA) includes work-exacerbated asthma (preexisting or concurrent asthma worsened by factors related to the workplace environment) and occupational asthma (new onset asthma attributed to the workplace environment). WRA is a preventable occupational lung disease associated with serious adverse health and socioeconomic outcomes. Among workers with similar occupational exposures, WRA diagnosis offers unique opportunities for prevention. The American Thoracic Society estimated that 15% of U.S. adults with asthma have asthma attributable to occupational factors. State-level information on the proportion of asthma that is WRA is limited but could be useful to prioritize and guide investigations and interventions. To estimate current asthma prevalence and the proportion of asthma that is WRA, CDC analyzed data from the 2006-2009 Behavioral Risk Factor Surveillance System (BRFSS) from 38 states and the District of Columbia (DC). This report summarizes the results of that analysis, which indicated that among ever-employed adults with current asthma, the overall proportion of current asthma that is WRA was 9.0%. State-specific proportions of asthma that are WRA ranged from 4.8% to 14.1%. Proportions of WRA were highest among persons aged 45-64 years (12.7%), blacks (12.5%), and persons of other races (11.8%). These findings provide a baseline that state and national health agencies can use to monitor the proportion of WRA among persons with current asthma. Enhancing WRA surveillance through routine collection of industry and occupation information will greatly increase understanding of WRA.     

Clinical evaluation, management, and prevention of work-related asthma

Work-related asthma (WRA) is asthma that is attributable to, or is made worse by, environmental exposures in the workplace. WRA has become the most prevalent occupational lung disease in developed countries, is more common than is generally recognized, and can be severe and disabling. Identification of workplace exposures causing and/or aggravating the asthma, and appropriate control or cessation of these exposures can often lead to reduction or even complete elimination of symptoms and disability. This depends on timely recognition and diagnosis of WRA. In this review, the diagnostic evaluation has been organized in a stepwise fashion to make it more practical for primary care physicians as well as physicians specializing in occupational diseases and asthma. WRA merits more widespread attention among clinicians, labor and management health and safety specialists, researchers, health care organizations, public health policy makers, industrial hygienists, and others interested in disease prevention.     

Work-related asthma and implications for the general public

Asthma has been increasing over the last two decades in the United States. The onset of asthma has also been increasingly reported as a result of occupational exposures to over 350 different agents. Work-related asthma (WRA) has become the most frequently diagnosed occupational respiratory illness. Epidemiologic studies from the United States reported WRA incidence rates of 29-710 cases per million workers per year and suggest that 10-25% of adult asthma is work related. Much can be learned about asthma in the general population from investigations of asthma in the workplace. Surveillance of WRA continues to highlight an important role for low molecular weight chemical sensitizers, as well as high molecular weight antigens. Additionally, recent reports implicate mixed exposures, including commercial cleaning solutions, solvents, and other respiratory irritants, as well as contamination in nonindustrial environments, including schools and offices. Investigations of WRA have demonstrated a clear dose-related increase in sensitization and symptoms for exposures to both chemical and protein sensitizers. High proportions of exposed working groups can be affected. Skin exposures may affect the likelihood of individuals developing respiratory symptoms. Atopy increases the risk of sensitization and illness from workplace exposure to antigens but not to chemical sensitizers. Irritant exposures can act as adjuvants among individuals exposed to sensitizing substances, increasing the proportion who become sensitized. Atopy might also be a result of irritant exposures in some persons. Occupational asthma often has important long-term adverse health and economic consequences but can resolve completely with timely control of exposures. Detailed study of such asthma "cures" may prove useful in understanding factors that influence asthmatic airway inflammation in the general population.     

Work-related asthma in the educational services industry: California, Massachusetts, Michigan, and New Jersey, 1993-2000

OBJECTIVES: To characterize work-related asthma (WRA) cases working in the educational services industry identified by state-based occupational disease surveillance systems. METHODS: We examined 2,995 WRA cases reported from 1993 to 2000 to four states: California, Massachusetts, Michigan, and New Jersey. RESULTS: A total of 265 (9%) WRA cases were employed in the educational services industry; 69% of cases were classified as new-onset asthma and 31% as work-aggravated asthma. New-onset asthma cases were further classified as occupational asthma (61%) or as reactive airways dysfunction syndrome (8%). The most frequently reported occupation was teachers and teachers' aides (54%). The most frequently reported agents were indoor air pollutants (28%), unspecified mold (16%), dusts (14%), and cleaning products (7%). CONCLUSIONS: Asthma within the educational services industry is an occupational health problem. The health of school employees should also be considered when initiatives addressing asthma among schoolchildren are instituted. The identification, elimination, and/or control of respiratory hazards are important factors for the protection of staff and students alike.     

Asthma diagnosed after 11 September 2001 among rescue and recovery workers: findings from the World Trade Center Health Registry

BACKGROUND: Studies have consistently documented declines in respiratory health after 11 September 2001 (9/11) among surviving first responders and other World Trade Center (WTC) rescue, recovery, and clean-up workers. OBJECTIVES: The goal of this study was to describe the risk of newly diagnosed asthma among WTC site workers and volunteers and to characterize its association with WTC site exposures. METHODS: We analyzed 2003-2004 interview data from the World Trade Center Health Registry for workers who did not have asthma before 9/11 (n = 25,748), estimating the risk of newly diagnosed asthma and its associations with WTC work history, including mask or respirator use. RESULTS: Newly diagnosed asthma was reported by 926 workers (3.6%). Earlier arrival and longer duration of work were significant risk factors, with independent dose responses (p < 0.001), as were exposure to the dust cloud and pile work. Among workers who arrived on 11 September, longer delays in the initial use of masks or respirators were associated with increased risk of asthma; adjusted odds ratios ranged from 1.63 [95% confidence interval (CI), 1.03-2.56) for 1 day of delay to 3.44 (95% CI, 1.43-8.25) for 16-40 weeks delay. CONCLUSIONS: The rate of self-reported newly diagnosed asthma was high in the study population and significantly associated with increased exposure to the WTC disaster site. Although we could not distinguish appropriate respiratory protection from inappropriate, we observed a moderate protective effect of mask or respirator use. The findings underscore the need for adequate and timely distribution of appropriate protective equipment and the enforcement of its use when other methods of controlling respiratory exposures are not feasible.     

Asthma incidence in wood-processing industries in Finland in a register-based population study

OBJECTIVES: This register-based population study determined incidence rates of clinically verified asthma among woodworkers, other blue-collar workers, and administrative personnel employed in wood-processing industries in Finland. Exposure to wood dust was under special scrutiny. METHODS: All Finns employed in wood-processing industries were followed for asthma incidence via record linkage in the years 1986-1998. Incident cases included people with asthma reimbursed for medication by the national health insurance or registered as having occupational asthma. Age-adjusted incidence rates and relative risks (RR) by gender were estimated for wood workers, other blue-collar workers, and administrative employees (referents) in wood industries. RESULTS: The relative risk of asthma was increased for all woodworkers among both genders [men: RR 1.5, 95% confidence interval (95% CI) 1.2-1.8; women: RR 1.5, 95% Cl 1.2-1.7]; a similarly elevated risk was also found for other blue-collar workers (men: RR 1.5, 95% Cl 1.2-1.8; women: RR 1.4, 95% Cl 1.2-1.6) in the same wood industries. Statistically increased relative risks were found for low and medium exposure to wood dust, but not for high exposure. Altogether 217 of the 4074 clinically verified asthma cases were reported as occupational asthma in the Finnish Register on Occupational Diseases. CONCLUSIONS: The incidence rates for asthma were significantly increased both among the woodworkers and the other blue-collar workers in wood industries but without a clear dose-response. Cases recognized as occupational asthma accounted for only a small part of the total asthma excess, indicating that much of the work-related asthma excess remains unrecognized in these industries.     

Early-life environmental risk factors for asthma: findings from the Children's Health Study

Early-life experiences and environmental exposures have been associated with childhood asthma. To investigate further whether the timing of such experiences and exposures is associated with the occurrence of asthma by 5 years of age, we conducted a prevalence case-control study nested within the Children's Health Study, a population-based study of > 4,000 school-aged children in 12 southern California communities. Cases were defined as physician-diagnosed asthma by age 5, and controls were asthma-free at study entry, frequency-matched on age, sex, and community of residence and countermatched on in utero exposure to maternal smoking. Telephone interviews were conducted with mothers to collect additional exposure and asthma histories. Conditional logistic regression models were fitted to estimate odds ratios (ORs) and 95% confidence intervals (CIs). Asthma diagnosis before 5 years of age was associated with exposures in the first year of life to wood or oil smoke, soot, or exhaust (OR = 1.74; 95% CI, 1.02-2.96), cockroaches (OR = 2.03; 95% CI, 1.03-4.02), herbicides (OR = 4.58; 95% CI, 1.36-15.43), pesticides (OR = 2.39; 95% CI, 1.17-4.89), and farm crops, farm dust, or farm animals (OR = 1.88; 95% CI, 1.07-3.28). The ORs for herbicide, pesticide, farm animal, and crops were largest among children with early-onset persistent asthma. The risk of asthma decreased with an increasing number of siblings (ptrend = 0.01). Day care attendance within the first 4 months of life was positively associated with early-onset transient wheezing (OR = 2.42; 95% CI, 1.28-4.59). In conclusion, environmental exposures during the first year of life are associated with childhood asthma risk.     

Work-related asthma symptoms and attitudes to the workplace

BACKGROUND: The Health & Safety Executive estimate that between 1500-3000 UK workers develop asthma through potentially avoidable workplace exposures each year. AIMS: To assess the perception of health, safety and the work environment by workers with symptoms suggestive of occupational asthma. METHODS: A total of 97 workers referred to hospital specialists with symptoms suggestive of occupational asthma were studied in order to investigate their attitudes to the workplace, safety and health. A qualitative study design using semi-structured telephone interviews at 2 months and 12 months following enrolment was used at 6 national UK centres with a special interest in occupational asthma. RESULTS: Many workers in the study felt let down by the workplace and management and perceived that a lack of health and safety measures had contributed to the development of their asthma symptoms. Many workers felt that their employers were 'uncaring' and were pursuing or considering medico-legal cases against them. CONCLUSIONS: Workers' perception of risk influences their behaviour in the workplace, and their own health beliefs potentially create barriers to changing this. It is essential to consider workers' perceptions when developing strategies to effect change within the workplace.     

Office work exposures and adult-onset asthma

BACKGROUND: Office exposures have been linked to symptoms of sick building syndrome, but their relation to the development of asthma has not been studied previously. These exposures have increasing importance because an increasing proportion of the workforce is working in office environments. OBJECTIVES: The aim of this study was to assess the relations of exposure to carbonless copy paper (CCP), paper dust, and fumes from photocopiers and printers to adult-onset asthma. METHODS: We conducted a population-based incident case-control study of adults 21-63 years of age living in the Pirkanmaa District in South Finland. All new clinically diagnosed cases (n = 521) of asthma were recruited during a 3-year study period. A random sample of the source population formed the controls (n = 1,016). This part focused on 133 cases and 316 controls who were office workers according to their current occupation classified by the 1988 International Standard Classification of Occupations. All participants answered a questionnaire on health, smoking, occupation, and exposures at work and home. Subjects with previous asthma were excluded. RESULTS: Exposures to paper dust [adjusted odds ratio (OR) = 1.97; 95% confidence interval (CI), 1.25-3.10] and CCP (OR = 1.66; 95% CI, 1.03-2.66) were related to significantly increased risk of adult-onset asthma. An exposure-response relation was observed between exposure to paper dust and risk of asthma. CONCLUSIONS: This study provides new evidence that exposures to paper dust and CCP in office work are related to increased risk of adult-onset asthma. Reduction of these exposures could prevent asthma in office workers. Clinicians seeing asthma patients should be aware of this link to office exposures.     

Moving knowledge of global burden into preventive action

BACKGROUND: Estimation of the global burden of disease and injury due to selected occupational factors is a topic of interest to policy makers, governments, and international bodies. The World Health Organization (WHO) has implemented a Comparative Risk Assessment (CRA) to estimate risk to exposed populations. METHODS: Estimates of the risk factor-burden relationships by age, sex, and WHO subregion were generated. Risk measurements (relative risks and mortality rates) for the health outcomes were determined primarily from studies published in peer review journals. The resulting burden was described as the attributable fraction of disease or injury, using both mortality and disability-adjusted life years (DALYs). RESULTS: The papers in this issue include discussions of worldwide mortality and morbidity from lung cancer, leukemia, and malignant mesothelioma arising from occupational exposures; mortality and morbidity from asthma, COPD, and pneumoconiosis; the global burden of low back pain; exposure to contaminated sharps injuries among health care workers; noise-induced hearing loss; and occupational injuries. Three papers focus on economic issues: estimation of net-costs for prevention of occupational low back pain; cost effectiveness of occupational health interventions; and the cost effectiveness of interventions in the prevention of silicosis. CONCLUSIONS: The magnitude of the occupational health burden in the world is overwhelming, and the causes and mechanisms are multiple and complex. Commitment from all stakeholders is imperative to translate economic progress into sustainable human development and well-being.     

Work-related asthma among professional cleaning women

The job of cleaning has developed dynamically as a working service, and women constitute the majority of all professional cleaning workers. Cleaners are at an increased risk of work-related asthma (WRA). This study characterizes work-related respiratory symptoms reported by female cleaners, evaluates any associated factors of WRA, and shows diagnostic management of medical certification. The study group comprised 50 professional cleaning women referred to our Occupational Diseases Department due to suspicion of occupational asthma (OA). A questionnaire, skin prick tests, serum specific IgE antibodies, and specific inhalant challenge were performed in all of the participants. Work-related asthma was recognized in 46% of symptomatic cleaners, of whom 15 were considered as having work-exacerbated asthma (WEA) and 8 as having OA. Sensitization to latex and disinfectants played an important role as a causative agent in OA of cleaners.     

Traffic density and stationary sources of air pollution associated with wheeze, asthma, and immunoglobulin E from birth to age 5 years among New York City children

Exposures to ambient air traffic-related pollutants and their sources have been associated with respiratory and asthma morbidity in children. However, longitudinal investigation of the effects of traffic-related exposures during early childhood is limited. We examined associations of residential proximity and density of traffic and stationary sources of air pollution with wheeze, asthma, and immunoglobulin (Ig) E among New York City children between birth and age 5 years.Subjects included 593 Dominican and African American participants from the Columbia Center for Children's Environmental Health cohort. Prenatally, through age 5 years, residential and respiratory health data were collected every 3–6 months. At ages 2, 3, and 5 years, serum IgE was measured. Spatial data on the proximity and density of roadways and built environment were collected for a 250 m buffer around subjects' homes. Associations of wheeze, asthma, total IgE, and allergen-specific IgE with prenatal, earlier childhood, and concurrent exposures to air pollution sources were analyzed using generalized estimating equations or logistic regression.In repeated measures analyses, concurrent residential density of four-way intersections was associated significantly with wheeze (odds ratio: 1.26; 95% confidence interval [CI]: 1.01, 1.57). Age 1 exposures also were associated with wheeze at subsequent ages. Concurrent proximity to highway was associated more strongly with total IgE (ratio of the geometric mean levels: 1.25; 95% CI: 1.09, 1.42) than were prenatal or earlier childhood exposures. Positive associations also were observed between percent commercial building area and asthma, wheeze, and IgE and between proximity to stationary sources of air pollution and asthma.Longitudinal investigation suggests that among Dominican and African American children living in Northern Manhattan and South Bronx during ages 0–5 years, residence in neighborhoods with high density of traffic and industrial facilities may contribute to chronic respiratory morbidity, and concurrent, prenatal, and earlier childhood exposures may be important. These findings may have broad implications for other urban populations that commonly have high asthma prevalence and exposure to a high density of traffic and stationary air pollution sources.     

Prevalence and predictors of asthma in working groups in British Columbia

We evaluated the prevalence of asthma and its predictors in studies of several male working groups: 619 cedar sawmill, 724 grain elevator, 399 pulpmill, 798 aluminum smelter, and 1,127 unexposed workers. These workers had taken part in health studies for assessment of chronic respiratory effects of various workplace exposures between 1979 and 1982. The American Thoracic Society Adult Questionnaire (ATS-DLD-78) was used for these studies. Allergy skin tests were also performed. The participation rates were > 80%. The overall prevalance of physician-diagnosed asthma was 4.6%, and current asthma 3%. The prevalence of asthma after employment in the current industry, as a surrogate for work-related asthma, was 3.9 times higher in cedar sawmill workers, 2.2 times higher in pulpmill and aluminum smelter workers, and 1.7 times higher in grain elevator workers compared with unexposed workers. Atopy and a positive parental history of asthma, but not smoking, were important risk factors for asthma before the onset of first employment. Also, for asthma after employment in the current industry, atopy and a positive parental history of asthma were important risk factors. Smoking was associated with a significant reduction in the risk for asthma after employment in the current industry. Within specific work groups, the prevalence of atopy was significantly higher among pulpmill workers with asthma after employment in current industry than those without asthma. Conversely, cedar sawmill workers who had asthma after employment in the current industry were nonatopic and nonsmokers.     

Respiratory symptoms and lung function in workers in heavy and highway construction: a cross-sectional study.

BACKGROUND: Occupational exposures for workers in heavy and highway (HH) construction include cement-containing dusts and diesel exhaust (DE). To investigate possible health effects, respiratory symptoms and lung function were examined in laborers, tunnel workers (TW), and operating engineers (OE) in HH and tunnel construction. The principal outcome of interest was airways disease. METHODS: Subjects were recruited through their unions. Medical and occupational histories and flow-volume loops were obtained. Based on self-report, asthma and chronic bronchitis were categorized as (1) physician-diagnosed or (2) for asthma, undiagnosed likely, and (3) for chronic bronchitis, symptomatic. Trade and time in the union were used as surrogates of exposure. Prevalence of asthma and chronic bronchitis, lung function outcome, and relationships with exposure variables were examined. RESULTS: Data were obtained on 389 workers: 186 laborers, 45 TWs, and 158 OEs. Prevalence of asthma was 13 and 11.4% for laborers (including TW) and OEs, respectively, and of symptomatic chronic bronchitis, 6.5 and 1.9%, respectively. Odds ratios (OR) for undiagnosed asthma likely were significantly elevated in TWs compared to OEs, and marginally elevated for chronic bronchitis. Inverse relationships were observed between time in the union, and risk for asthma and chronic bronchitis. Asthma (physician-diagnosed or undiagnosed likely) predicted lower FEV(1). Current cigarette use was associated with chronic bronchitis but not asthma. CONCLUSIONS: TWs, laborers, and OEs in HH construction are at increased risk for asthma. TWs also appear to be at increased risk for chronic bronchitis. Our data suggest that symptomatic workers are self-selecting out of their trade. Asthma was associated with lower lung function in those affected.     

Asthma risk, cleaning activities and use of specific cleaning products among Spanish indoor cleaners

OBJECTIVES: Recent studies have shown an excess risk of asthma for cleaners, but it is not clear which cleaning-related exposures induce or aggravate asthma. METHODS: Risk factors for asthma were studied among indoor cleaners participating in the Spanish part of the European Community Respiratory Health Survey in 1992. In 1998, 78 of the 91 subjects reporting cleaning-related jobs in 1992 were identified. Of these, 67 indoor cleaners were interviewed by telephone about their cleaning activities and their use of cleaning products in 1992. These data were related to asthma prevalence in 1992, and the cleaners were compared with a reference group of office workers. RESULTS: Asthma prevalence was 1.7 times higher [95% confidence interval (95% CI) 1.1-2.6] among the cleaners than among the referents, being highest among private home cleaners (3.3, 95% CI 1.9-5.8). The prevalence of housedust mite sensitization amounted to 28% for the home cleaners and was significantly (P<0.01) higher than for other indoor cleaners (3%), but similar to the corresponding prevalence of office workers (22%). More than half of the cleaners reported work-related respiratory symptoms. The asthma risk of the home cleaners was mainly associated with kitchen cleaning and furniture polishing, with the use of oven sprays and polishes. CONCLUSIONS: The asthma risk of Spanish cleaners is primarily related to the cleaning of private homes. This relationship may be explained by the use of sprays and other products in kitchen cleaning and furniture polishing.     

Exposures to blood and body fluids in Brazilian primary health care

Background Primary health care workers (HCWs) represent a growingoccupational group worldwide. They are at risk of infectionwith blood-borne pathogens because of occupational exposuresto blood and body fluids (BBF). Aim To investigate BBF exposure and its associated factors amongprimary HCWs. Methods Cross-sectional study among workers from municipal primaryhealth care centres in Florianópolis, Southern Brazil.Workers who belonged to occupational categories that involvedBBF exposures during the preceding 12 months were interviewedand included in the data analysis. Results A total of 1077 workers participated. The mean incidencerate of occupational BBF exposures was 11.9 per 100 full-timeequivalent worker-years (95% confidence interval: 8.4–15.3).The cumulative prevalence was 7% during the 12 months precedingthe interview. University-level education, employment as a nurseassistant, dental assistant or dentist, higher workload score,inadequate working conditions, having sustained a previous occupationalaccident and current smoking were associated with BBF exposures(P 0.05). Conclusions Primary Health Care Centres are working environmentsin which workers are at risk of BBF exposures. Exposure surveillancesystems should be created to monitor their occurrence and toguide the implementation of preventive strategies.     

Risk for occupational transmission of HIV infection among health care workers

The aim of this study was to evaluate the HIV seroconversion rate associated with different types of occupational exposures in health care workers. A longitudinal study was conducted from January 1986 to October 1992 in a teaching hospital in Spain, where HIV infection is prevalent among patients. Each health care worker was asked to complete a questionnaire regarding age, sex, staff category, lace of exposure, other exposures, type of exposure, body fluid, infected material and HIV status of source patient. These health care workers were then followed up at 6 weeks, 3 months, 6 months and 12 months with repeated test for HIV antibody. Four hundred twenty three reports of occupational exposure were analysed. Nursing was the profession with more exposures (42.8%). Ninety five percent of total exposures were percutaneous, 4% mucous membrane contacts and 1% skin contacts, 88.3% were described as blood contact and 71.8% had resulted from needlestick and suture needles. Exposures from HIV-positive patients comprised 23.2% of occupational exposures. There was a significant difference in the length of follow-up in physicians (p=0.00009) and nurses (p=0.00001), when we compared HIV-positive patients with patients in whom the HIV status was unknown or negative. The HIV seroconversion rate was 0.00%. We consider that the risk of acquiring HIV infection via contact with a patient is low, but not zero. Well documented cases of seroconversion have been published. Because it is often impossible to know a patient's infection status, health care workers should follow for rotine the universal precautions for all patients when there is a possibility of exposure to blood or other body fluid. Equally important is the development of new techniques to minimize the risk of exposures to blood.     

Case-by-case assessment of adult-onset asthma attributable to occupational exposures among members of a health maintenance organization

OBJECTIVE: In a general population of employed persons with health insurance, what proportion of adult-onset asthma is caused by occupational exposures? METHOD: We conducted a 2-year prospective study to identify adult-onset asthma among health maintenance organization (HMO) members. Telephone interviews regarding occupational exposures, symptoms, medication use, and triggers were used to assess likelihood of work-related asthma for each case. Weighted estimating equations were used to adjust the proportion of asthma attributable to workplace exposures for factors associated with interview participation. RESULTS: Overall, 29% (95% confidence interval, 25-34%) of adult-onset asthma was attributable to workplace exposures; 26% (21-30%) and 22% (18-27%) of cases had asthma attributable to occupational irritant and sensitizer exposures, respectively. CONCLUSIONS: Occupational exposures, including irritants, are important causes of adult-onset asthma.